Arrangements of the above general type are known for acoustic post-locating or fine locating of faults in buried electrical lines. Such arrangements may include a receiver unit consisting of a magnetic field sensor, an acoustic sensor and an indicator or display unit, for detecting the electromagnetic signals and the acoustic signals emitted by the fault at the fault location when voltage pulses are applied to the electrical line. Then the fault can be located by evaluating the acoustic signals in connection with the electromagnetic signals.
The deficiency in such a post-locating or fine locating is that external acoustic interference noises often arise and are superimposed on the actual useful acoustic signals emitted by the electrical fault, which impairs or prevents an exact ground-borne noise location. These interference sources exist in environmental influences, such as wind and rain, street traffic and pedestrians, which make noises that are acoustically superimposed on the useful signal.